Circular chipping device



Dec. 27, 1966 T. 5. LITTLE 3,294,132

CIRCULAR CHIPPING DEVICE 2 Sheets-Sheet 1 Filed Oct. 8, 1964 n Q 2 g "3 N Z 7 M A 9 RYK' ml g, Pix V2 Lnf uu n,

INVENTOR PA'T'E N'T' AG ENTH Dec. 27, 1966 T. B. LITTLE 3,294,132

CIRCULAR CHIPPING DEVI CE Filed Oct. 8, 1964 2 Sheets-Sheet 2 INVI'LN'I'OR 7710mm; [9.Ll'fiie United States Patent Filed Oct. 8, 1964, Ser. No. 402,548 7 Claims. (Cl. 144-218) This invention relates to a circular chipping device for producing wood chips suitable for use in the production of wood pulp, particle boards, and the like.

In the handling and treatment of logs, it frequently becomes necessary to saw the logs up into shorter lengths. For instance, conventional wood chippers as used in pulp production, require the use of logs of short, generally uniform length. Saws, such as the common type of circular saw, are employed to cut the logs into shorter lengths. These saws, of course, produce sawdust which has very limited commercial value and, therefore, a substantial wastage of wood occurs as a result.

It is an object of the present invention to provide a wood chipping device which may be employed to cut logs into shorter length, the wood removed as a result of the out being substantially all in the form of chips suitable for use in the production of wood pulp of good quality.

The invention resides in a wood chipping device comprising a circular frame, such as a disk, having an axial hub for rotative mounting of the frame. A plurality of circumferentially spaced knives are mounted on the periphery of the frame, each knife having a first cutting edge substantially parallel to the axis of the frame and a second cutting edge extending in angular relation to the first cutting edge. Each series of cutting edges are adapted to move in a circular path.

The invention will be described with reference to the accompanying drawing, in which FIGURE 1 is a side elevation of a device in accordance with the invention,

FIGURE 2 is a section on line 2-2 of FIGURE 1,

FIGURE 3 is an enlarged partial side elevation showing a knife mounting means,

FIGURE 4 is a perspective view of a knife in accordance with the invention,

FIGURE 5 is an end view of the knife shown in FIG- URE 4,

FIGURE 6 is a side elevation of the knife,

FIGURE 7 is a sectional view of a knife clamping arrangement, and

FIGURES 8 and 9 are perspective views of alternative forms of knives.

Referring to FIGURES 1 to 5, inclusive, 10 is a circular frame or disk having a hub 11 fixed to the axial portion thereof. The hub is adapted to provide means for mounting the disk on a driven shaft 9 for rotation of the disk.

A plurality of knives 12 are removably mounted on the periphery of the disk. As shown, the periphery is provided with .a series of uniformly and circumferentially spaced recesses 13. Each recess has an inclined seating surface 14 for reception of the body 15 of the knife. Surface 14 may be provided with positioning ribs 16 to engage the side surfaces of the knife body. A suitable degree of inclination of surface 14 is about 45 to a radius passing through the outer end thereof.

A clamping plate 17 is disposed in each recess 13 for clamping the respective knife in position therein. The clamp 17 has an inclined surface 18 complementary to and arranged to be placed in opposed relation to surface 14 with the knife body clamped therebetween. The surface 18 is provided with knife body positioning ribs 3,294,132 Patented Dec. 27, 1966 19. A screw 20 secures the clamp in clamping position.

Each knife has a somewhat widened cutting head 21 formed at one end of the body 15 and such head has a transverse cutting edge 22 at the end thereof. Edge 22 is formed by sharpening the end face 23 at a suitable angle which, as shown in FIGURE 6 by way of example, may be about 43 to the outer face 24 of the knife. The edge 22 is coincident with the plane of the inner face 25 of the knife. It will be observed that the edge 22 is arranged to be disposed in parallel relation to the axis of the disk.

The cutting head, in the modification shown, is provided with a wing 26 at each side thereof and depending from the face 25. Each wing 26 has a cutting edge 27 extending angularly from each end of the cutting edge- 22. Each cutting edge 27 lies in a plane extending at right angles to cutting edge 22 and, as shown, in a plane lying at an angle of about with face 23. However, cutting edges 27 may lie in a plane at an angle of about to to cutting edge 22. Each wing has an outer side face 28 perpendicular to cutting edge 22 and an inner side face 29 which may be disposed at an angle of about 38 with face 28, faces 28 and 29 terminating in a sharpened edge 30. Cutting edge 22 may have a length of 2 inches to one-half inch. Each cutting edge 27 may have a length of inch to 1 inch.

As clearly shown in FIGURE 3, the cutting edges 22 and 27 of the knives are disposed outwardly of the peripheral surfaces of the disk and clamps 17 for engagement with a log surface applied thereto. It will be apparent that the cutting edges 22 and 27 of each knife will engage a log surface substantially simultaneously, edge 22 acting to effect a cut in the grainwise direction of the log and edges 27 in a cross grain direction whereby a chip is severed from the log. The thickness of such chip will, of course, depend upon the extent of projection of the cutting heads beyond the peripheral surface of the disk as constituted by the curved edge surfaces 31 of the clamps 17 and the adjoining curved edge surfaces 32 of the disk.

It will be appreciated that the cutting edges of the knives will require sharpening and thus, it is advisable that means be provided for adjusting the position of the knives to compensate for the sharpening procedure. To this end, a screw 33 is provided in the inner end of the body of each knife, the head portion of the screw being located in a recess 34 and seated on a surface 35 of the disk.

Passage means are provided for receiving the produced chips and discharging them laterally of the disk. This means comprises a chip-receiving passage 36 in the disk adjoining each knife cutting head and leading into a circular recess 37 in the disk. The edge 38 of each recess may be bevelled, as shown, to facilitate discharge of the chips.

A chip bar 39 of high speed steel is preferably provided on the disk in opposed relation to each cutting head.

It will be apparent that various alternative knife structures may be employed. A modified form of structure is illustrated in FIGURES 8 and 9 and including knives 40 and 41 adapted to be mounted in alternate order about the periphery of the disk 10. Each knife 40 and 41 is similar to knife 12 and has a transverse cutting edge 42, 43 but omits the wings 26. Knife 40 has a scoring member 44 mounted on its end face 45 and having a cutting edge 46 extending angularly from one end of cutting edge 42. Knife 41 has a scoring member 47 mounted on its end face 48 and having a cutting edge 49 extending angularly from one end of cutting edge 43. However,

the scoring member 47 of knife 41 is located at an end of cutting edge 43 which is opposite to the end of cutting edge 42 on which scoring member 44 is mounted.

I claim:

1. A wood chipping device comprising a disk having an axial hub for rota'tive mounting of said disk, a plurality of knives mounted on the periphery of said disk, said knives being arranged in a single circular row, each said knife having a unitary body, a first cutting edge on said body substantially parallel to the axis of said disk and a second cutting edge on said body extending angularly from one end of the said first cutting edge, said first cutting edges lying in a first common circular path, said second cutting edges lying in a second common circular path and in a plane at an angle of about 90-=to 160 to said disk axis.

2. A wood chipping device as defined in claim 1, each of said end cutting edges lying in a plane at an angle of approximately 90 to 160 to said intermediate cutting edge.

3. A wood chipping device as defined in claim 1, each of said end cutting edges lying in a plane at an angle of approximately 90 to said intermediate cutting edge.

4. A wood chipping device as defined in claim 2,

wherein said intermediate cutting edge has a length of two inches to one-half inch.

5. A wood chipping device as defined in claim 1, wherein each of said end cutting edges has a length of inch to one inch.

stantially parallel to the axis of said frame and a second cutting edge adjoining one end of said first cutting edge and disposed substantially right angularly with respect thereto, said first cutting edges having a circular path of movement, and said second cutting edges having a circular path of movement of greater diameter than that of said first cutting edges, each alternate one of said knives has said second cutting edge at an end thereof opposite to that of each of the others of said knives.

References Cited by the Examiner UNITED STATES PATENTS 3,128,804 4/1964 Scott 144-241 3,144,058 8/1964 Carter 143-133 3,219,076 11/1965 Logan et al. 144241 WILLIAM W. DYER, ]R., Primary Examiner.

W. D. BRAY, Assistant Examiner. 

7. A WOOD CHIPPING DEVICE COMPRSING A CIRCULAR FRAME HAVING AN AXIAL HUB FOR ROTATIVE MOUNTING OF SAID FRAME, A PLURALITY OF KNIVES MOUNTED ON THE PERIPHERY OF SAID FRAME, EACH SAID KNIFE HAVING A FIRST CUTTING EDGE SUBSTANTIALLY PARALLEL TO THE AXIS OF SAID FRAME AND A SECOND CUTTING EDGE ADJOINING ONE END OF SAID FIRST CUTTING EDGE AND DISPOSED SUBSTANTIALLY RIGHT ANGULARLY WITH RESPECT THERETO, SAID FIRST CUTTING EDGES HAVING A CIRCULAR PATH OF MOVEMENT, AND SAID SECOND CUTTING EDGES HAVING A CIRCULAR PATH OF MOVEMENT OF GREATER DIAMETER THAN THAT OF SAID FIRST CUTTING EDGES, EACH ALTERNATE ONE OF SAID KNIVES HAS SAID SECOND CUTTING EDGE AT AN END THEREOF OPPOSITE TO THAT OF EACH OF THE OTHERS OF SAID KNIVES. 